Field of the Invention. The present invention relates to a semiconductor memory device and a fabrication method thereof, and more particularly to a semiconductor memory device comprising memory cells with a write voltage controlled by adjusting lengths and doping concentrations of base regions and a fabricating method of the same.
Description of the Related Art A semiconductor memory device is a device used for storing information and is an apparatus that enables human memory and recording ability to be realized by electronic means. The semiconductor memory devices are useful for constructing circuits because they can easily enable to turn on and off electricity even by low power. Currently, most electronic devices such as computers, smart phones and the like use semiconductor memories.
However, recently, as the fourth industrial revolution such as an artificial intelligence (AI) and an autonomous driving automobile has begun, the demand for an ultra high performance memory has exploded. But, the development of semiconductor memory devices has been limited due to the limitations of the fine processing technology. This deteriorates the overall performance of the electronic devices determined by the performance of the semiconductor memory device.
Accordingly, there is a need of techniques for improving the performance of semiconductor memory devices.